Improvement in adjustable spirit-levels



E. A. 80C. M. STRATTQN.

improvement in Adjustable'Spirit-Leveis.

Patented July 16, 1872.

AM. IIIIITO-LITHOGRAPIIIC W MX/0SBOKNE5 PROCESS] PATENT OEEIoE.

EDWIN A. STRATTON AND CHARLES STRATTON', OF GREENFIELD, MASS.

IMPROVEMENT IN ADJUSTABLE SPIRIT-LEVELS.

Specification forming part of Letters Patent No. 129,183, dated July 16, 1872.

SPECIFICATION.

To all whom it may concern:

Be it known that we, EDWIN A. STRATTON and CHARLES M. STRATTON, of Greenfield, in the county of Franklin and State of Massachusetts, have invented certain Improvements in Spirit-Levels, of which the following is a specification, referencebein g had to the accompanying drawing.

Our invention relates to spirit-levels; and our improvement consists in so forming and arranging the parts that the level may be readilytrued up or adjusted when necessary.

Figure 1 is a top-plan view of the level with the top plate 0 detached. Fig. 2 is avertical section of the same through the line 00 .00 of Fig. 1.

Levels have heretofore been constructed in which the bulb containing the fluid was made adjustable, but these are liable to get out of order from various causes. The object of our invention is to produce a level which shall be simple and easily adjusted.

In constructing our improved level the bulb B, containing the fluid, is fastened permanently in the body A in the ordinary manner. We then provide an indicator or index, a, in the form of a slide, provided at one end with a slot, through which a screw, 0, passes, to hold the slide in place and allow it to be adjusted when desired. At the opposite end of this slide is a cross-bar or pointer, e, which is set or adjusted at the center of the bubble when the level i is set in a perfectly horizontal position.

It is obvious that the index may be constructed in a variety of ways, and it may be arranged to be adjusted without removing the top plate, the only requirement being that it shall be adjustable and be capable of being fastened'in place. Hence we do not limit ourselves to any special form of device.

The operation of adjusting the level is as follows: Place the level in an exact level position and remove the top plate 0; then loosen the screw- 0 move the indicator to the center of the bubble, tighten the screw 0, and replace the top plate 0. The level is then ready for use.

Having thus described our invention, what we claim is- A spirit-level provided with an index or 

